1. Field of the Invention
The present invention relates to an electronic apparatus in which a second housing is openably/closably and rotatably coupled with respect to a first housing.
2. Description of the Related Art
In portable electronic apparatuses such as laptop personal computers and mobile phones, a configuration in which an upper housing having a display screen is openably/closably coupled with respect to a lower housing having a keyboard and a push button has been widely used. Such an electronic apparatus is folded so that the upper housing is laid over the lower housing when the apparatus is carried around, and at the time of operation, the upper housing is opened so that the keyboard and push button may be used; thus the portability of the apparatus is increased without downsizing the keyboard and push button.
Further, in recent years, electronic apparatuses have also been known in which an upper housing is openably/closably and rotatably coupled with respect to a lower housing (see, for example, Japanese Patent Application Publication No. 8-191420 and Japanese Patent Application Publication No. 2004-118409). For example, when a number of persons see the display screen of one personal computer, by rotating the upper housing to which a display screen is disposed with respect to the lower housing, the display screen can be easily turned to each person. Moreover, in recent years, in addition to a conventional input operation mode using a keyboard or the like, a tablet mode using a touch pen for touching the display screen and moving on the display screen to enter instructions has been incorporated into a personal computer. Furthermore, in such a personal computer, in addition to a touch panel for giving instructions by contact using a touch pen and a finger, an input device that incorporates an electromagnetic induction-type digitizer on the back of the display screen, and detects the position on the display screen indicated with a stylus pen is also used. In the tablet mode, by rotating the upper housing with respect to the lower housing, and laying the upper housing over the lower housing with the display screen turned outward, the personal computer can be easily carried around, and input with the touch pen becomes easy. In this manner, by openably/closably and rotatably coupling the upper housing with respect to the lower housing, the operability of the electronic apparatus can further be improved.
Incidentally, although in an electronic apparatus in which an upper housing is rotatable with respect to a lower housing, it is usually assumed that the upper housing is rotated with the upper housing standing with respect to the lower housing, practically, a user who is not familiar with the operation of the apparatus sometimes rotates the upper housing with the apparatus closed or with the apparatus widely opened, which may cause the upper housing and the lower housing to rub against each other and get damaged, or may cause the breakage of the display screen. Conventionally, although a hook to fix the upper housing to the lower housing is sometimes provided on the top of the display screen in order to prevent the rotation in a closed state, there are problems that the appearance is deteriorated, and a case where the upper housing is rotated with the upper housing widely opened cannot be addressed.